/*
剑指 Offer 12. 矩阵中的路径
 */
public class Offer12 {

  public static void main(String[] args) {
    char[][]tmep = new char[][]{
            {'A','B','C','E'},{'S','F','C','S'},{'A','D','E','E'}
    };
    System.out.println(new Offer12().exist(tmep, "ABCCED"));

  }

  public boolean exist(char[][] board, String word) {
    char[] words = word.toCharArray();
    for (int i = 0; i < board.length; i++) {
      for (int j = 0; j < board[0].length; j++) {
        if(dfs(board, words, i, j, 0)) return true;
      }
    }
    return false;
  }

  private boolean dfs(char[][] board, char[] words, int i, int j, int k) {
    if(i >= board.length || i < 0 || j >= board[0].length || j < 0 || board[i][j] != words[k]) return false;
    if (k == words.length - 1) return true;
    board[i][j] = '\0';
    boolean res = dfs(board, words, i + 1, j, k + 1) || dfs(board, words, i - 1, j, k + 1) ||
            dfs(board, words, i, j + 1, k + 1) || dfs(board, words, i , j - 1, k + 1);
    board[i][j] = words[k];
    return res;
  }

}
